### History of Waste Management - Kagawa Prefecture - April 2007 to the 2020s

### History of Waste Management - Kagawa Prefecture - April 2007 to the 2020s

#### 2007: Development and Introduction of Technology
In 2007 Ikeda Construction Co. Ltd. in Kagawa Prefecture developed a technology to solidify and improve dredged sludge generated at construction sites. This technology enabled the reuse of approximately 10000 tons of dredged sludge annually as construction materials such as road base materials. Compared to traditional methods costs were reduced by about 30% and carbon dioxide emissions were successfully lowered. This initiative became a model case for recycling construction waste in Kagawa Prefecture with technology deployment across the region gaining high praise from local governments and the construction industry.

#### 2010s: Expansion of Application
During the 2010s the application of this technology expanded throughout Kagawa Prefecture. Ikeda Construction Co. Ltd. collaborated with local governments to promote its use at port and river dredging sites. The gypsum-based soil improvement solidification material was further refined enhancing processing efficiency. During this period approximately 12000 tons of dredged sludge were reused annually in Kagawa Prefecture widely utilized in public and private construction projects. The stabilization of the improved soil quality also advanced its use in road construction and levee reinforcement.

#### 2020s: Technological Evolution and Deployment
In the 2020s Ikeda Construction Co. Ltd. introduced high-density thin-layer dredging vessels and pump ships achieving greater efficiency in dredging operations. Using gypsum-based soil improvement solidification material uniform improvement of dredged sludge was made possible enabling immediate transportation and early reuse. This technology now facilitates the recycling of over 10000 tons of sludge annually achieving both cost reductions and environmental impact mitigation. Kagawa Prefecture has also established the "Kagawa Prefecture Construction Waste Recycling Guidelines" promoting the widespread adoption of Ikeda Construction's technology throughout the prefecture.

#### Future Outlook
In Kagawa Prefecture further technological innovation and the expansion of local recycling efforts are anticipated. Ikeda Construction Co. Ltd. plans to develop new construction materials utilizing improved soil aiming to increase annual processing capacity to 15000 tons in the future. This initiative will continue to attract nationwide attention as a pioneering model case for realizing a sustainable society.